Plastic rubbish greater threat than climate change

THE world's leading expert on the poisoning of the oceans said he was "utterly shocked" at the increase in plastic floating on the sea in the past five years and warned that it potentially posed a bigger threat to the planet than climate change.

Charles J Moore, a captain in the US merchant marine and founder of a leading Ocean research group, has just finished his first in-depth survey of the Great Pacific Garbage Patch - one of five major expanses of plastic drifting in the world's oceans - since 2009.

"It's choking our future in ways that most of us are barely aware," said Captain Moore, who first caught sight of the patch in the North Pacific Ocean in 1997, while returning to southern California after the Los Angeles to Hawaii TransPacific yacht race.

He has since revisited the area with a team of scientists 10 times, noting an alarming increase in rubbish.

"Although it was my tenth voyage to the area, I was utterly shocked to see the enormous increase in the quantity of plastic waste since my last trip in 2009.

Plastics of every description, from toothbrushes to tires to unidentifiable fragments too numerous to count floating for hundreds of miles without end," Captain Moore wrote in a column in the New York Times.

"We even came upon a floating island bolstered by dozens of plastic buoys used in oyster aquaculture that had solid areas you could walk on," he added.

Plastics are now one of the most common pollutants of ocean waters in the world. Pushed by winds, tides and currents, plastic particles form with other debris into large, swirling glue-like accumulation zones, known to oceanographers as "gyres", which comprise as much as 40 per cent of the planet's ocean surface, said Captain Moore, who founded the Algalita Marine Research Institute in Long Beach, California.

In a previous study of Southern California's urban centres, he calculated that they spilled 2.3bn pieces of plastic - from polystyrene foam to tiny fragments and pellets - into the area's coastal waters in just three days of monitoring.

Once in the sea, the plastics biodegrade extremely slowly, breaking into tiny fragments in a centuries-long process.

During this period, they entangle and slowly kills millions of sea creatures, while hundreds of species mistake the plastic for food, ingesting toxicants that cause liver and stomach problems in fish and birds and often choke them to death.

"We suspect that more animals are killed by vagrant plastic waste than by even climate change - a hypothesis that needs to be seriously tested," Captain Moore said.

The problem is exacerbated by the fishing industry, which uses huge amounts of plastics in its floats, lines and nets that often get lost accidentally and in storms.

Although a handful of methods do exist to help reduce the volume of plastic at sea, they pale into insignificance against the scale of the garbage heaps.

"The reality is that only by preventing manmade debris - most of which is disposable plastic - from getting into the ocean in the first place will a measurable reduction in the ocean's plastic load be accomplished."

"The real challenge is to combat an economic model that thrives on wasteful products and packaging and leaves the associated problem of clean-up costs.

Changing the way we produce and consume plastics is a challenge greater than reining in our production of carbon dioxide," Captain Moore added.

How to reduce ocean plastic

There are no high-tech methods for reducing the volume of plastic at sea. In fact, those techniques we do have are surprisingly mundane.

Plastic bag tax: The best way to reduce the amount of plastic is to use less of it, and the best way to do this is to cut down on plastic bags.

Sieve-like skimmers: These come in a variety of shapes and sizes but essentially they aim to scoop up debris out of the water.

Screens: Covering gutters and catch basins in urban areas with 5mm screens has reduced the amount of debris flowing down rivers into the sea.

Circular economy: The basic idea is to recycle as much as possible and to design products in such a way that as little has to be thrown away as possible.